Abrasive rolls



Oct. 14, 1958 'F. uf FANNlNG 25855,;1-32

ABRASIVE ROLLS Filed :April 29. .1958

y@ ffy of ma ATTORNEY United States Patent O ABRAsIvE ROLLS Frank U. Fanning, Dayton, Ohio, assignor to Lectro Manufacturing, Inc., Middletown, Ohio, a corporation of Ohio Application April 29, 1958, Serial No. 731,680

8 Claims. (Cl. 51--190) This invention relates to improvements in forming and securing abrasive rolls.

More particularly this invention concerns the forming of a roll of abrasive material in a manner to insure efficient bonding `action while at the same time applying the bonding material to only a very small portion of the total roll.

Abrasive rolls presently available have several drawbacks in the manner of securing the same in a wound condition. In these past structures a considerable percentage of the entire area of the abrasive surface must be covered with the bonding material, thus reducing the abrasive effectiveness of a large portion of the wound roll. Further, the usual method of simply coating a portion of an abrasive sheet and thence winding the same into a roll results in a structure having very poor securing characteristics as the joining -of successive convolutions is effected between the'abrasive surface of one convolution and the backing or fabric of the next succeeding convolution. This forms avery poor bond and the resulting roll tends to y apart in use. Attempts have been made to overcome this weakness by punching a line of holes through the abrasive sheet, adjacent one edge, prior to the application of bonding material in an attempt to effect a direct bonding between successive layers of the backing material. This method is well illustrated by Patent N o. 2,290,098 to Field. Thisv punched structure has several drawbacks in that utilization of such a structure requires a punching operation to remove a portion of the sheet; the location of the holes, back from one edge of the sheet, still requires an application of glue over a considerable portion of the sheet, usually up to 1A of its width; and the resulting bond is still sub* ject to failure.

An object of this invention is to provide an abrasive roll in which direct bonding is obtained 'between the backing material of successive layers of the roll.

Another object of this invention is to provide an abrasive roll which is rmly and effectively secured through application of a bonding material to only a very narrow strip along one edge.

Another object of this invention is to provide an abraive roll which Will not unwind or ily apart through use Iand which will require a minimum amount of bonding material in the formation thereof.

Another object of this invention is to provid-e a method for forming an abrasive roll having a direct bond between the backing material layer of successive convolutions and for insuring penetration of this bonding material through each layer to effect this bond.

These and other objects and advantages of this invention will be apparent fro-m the following description and claims.

In the laccompanying drawings which illustrate by way of example various embodiments of this invention:

Fig. l represents a plan View of an abrasive sheet to be wound into an abrasive roll;

Fig. 2 is a front edge view of the sheet in Fig. 1 ready ,for application of a ybonding material thereto;

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Fig. 3 is an end view of an abrasive roll in the process of being formed by winding an abrasive sheet.

Fig. 4 is a side elevation view of a finished abrasive roll.

Fig. 5 is an enlarged fragmentary cross-sectional view along line 5-5 of Fig. 4.

The sheet 10 is a conventional abrasive sheet compris ing a base sheet having a coating of abrasive material secured to one surface 10a. This sheet 10 may be defined as having `a starting edge 11, a tail end 12, a bonding edge 13 and a second edge 14. The sheet 10 has numerous slits 15 projecting inwardly from bonding edge 13. These slits are preferably disposed at an acute angle with respect to edge 13 and are oriented to enter the sheet in the direction of travel of the abrasive sheet when being Wound as represented by the arrow in the center of Fig. 1. This preferred inclination of the slits 15 may also be defined as being toward the starting edge 11.

The slits 15 Vform a fringe of the edge portion 18 of sheet 10. Individual portions of this fringe are in the form of triangular flaps as generally defined by slit 15a, a portion of edge 13 as at 13a, and a base or unsevered side 16. The edge portion 18 of the sheet 10 is generally dened by aline roughly corresponding to the innermost end of the slits 15, here represented by dashed line 19.

In Fig. 2 the fringe or flaps 17 are shown bent or displaced out of the plane of the remainder of the sheet 10. This displacement is preferably towards the uncoated side of the sheet. With the flaps 17 in this displaced position, a bonding material is applied to the uncoated side of the sheet 10 in the area corresponding to the edge portion 18.

In Fig. 3 the sheet 10 is being Wound from the starting edge to form an abrasive roll. Incident to this winding the ilaps 17 are pressed back into the plane of the immediate adjacent portion of the sheet 10. Thus, ilaps such as 17a and 17b have been returned to alignment with the adjacent portions of the sheet While flap 17e is in the process of being bent back into such a position and 17d remains inthe displaced or bent position. Completion of the winding results in an abrasive roll 22 which is bonded at one end 23.

Fig. 5 represents the means or lines of bonding resulting from the structure and method of the instant invention. The layers of the convolution comprise the base sheet 25, the abrasive material 26 and the bonding material 271 The edge correspond-ing to the thickness of the abrasive sheet along the line of severance 15a of a ap is indicated at 30. The feature to Ibe here noted is that the bonding material forms an unbroken bond from the base sheet of one convolution to the base sheet of the next adjacent convolution. That is, lfor instance, the bonding material in the area 31 joins the base sheet on the surface represented by line 32, penetrates along an edge 30 to communicate with the bonding material area 31a and adheres to the base sheet on the surface represented by line 32a. Thus, a bond is secured directly between the base sheet material portions of successive convolutions. The bonding rnaterial utilized in this roll need only be applied to the portion 18 of the sheet 10. This application should be on the uncoated side of the sheet and particular attention must be paid to insure that the edges 13 and 15a are coated.

While the method of forming this structure should be readily apparent from the above description, the specific steps may be set forth as follows: Slitting an abrasive sheet in numerous places along one edge to form a fringe or a plurality of flaps, 'displacing the individual portions of the fringe or flaps, as by bending, toward the uncoated side of the sheet; applying a bonding material to the uncoated side of the sheet in the area corresponding t-o the previously made slits insuring that the bonding material thoroughly covers the edges of the individual flaps; Winding the sheet in the appropriate direction, with the abrasive material outwardly disposed; securing the roll in a wound condition and appropriately curing the bonding material.

Through the use of they structure and method herein set forth, it has been found that the depth of slit an l the area of bonding material application need cover onlyy a very narrow strip along the edge of the abrasive sheet. A lateral depth of slit and area of glue application as narrow as 1/16 inch has been found suflicient to create a bond which is stronger than the sheet material itself; that is, tearing of the sheet will .occur before failure of the bond between convolutions. amounts to utilizing the bonding material on only 17452 of the width as compared to the approximately 1A; width covering utilized in conventional structures.

While the invention has been described in connection with different embodiments thereof, it will Ibe understood that it is capable of further modification, and this application is intended to cover anyy variations, uses or adaptations of the invention following, in general, the principles of the invention including such departures in the present disclosure as come within known or customary practice in the art to which the invention pertains, and as may be applied to the essential features hereinbefore set forth and as fall within the scope of the invention or the limits of the appended claims.

Having thus described my invention, what l claim is:

l. An abrasive roll formed of ya plurality of convolutions of sheet material having abrasive material thereon, one edge of said sheet being slit inwardly from said edge at an acute angle relative to said edge said slits oriented in the direction of travel of said sheet when being wound and bonding material penetrating through said slits and joining successive convolutions of said sheet material t-o secure said roll in convoluted form.

2. An abrasive roll formed of a plurality of convolutions of sheet material having abrasive material thereon, one edge of said sheet fringed by a plurality of slits extending inwardly from said edge, said slits disposed at an acute angle with said edge and oriented in the direction of travel of said sheet when being wound, and bonding material penetrating through said slits and joining successive convolutions of said sheet material to secure said roll in convoluted for-m.

3. An abrasive roll formed of spirally Wound sheet material having an abrasive coating on one side thereof, said roll having a bonded end, the edge portion of said sheet On a conventional two inch strip this` corresponding to said bonded end fringed by a plurality of slits extending inwardly from the edge thereof, said slits disposed at an acute angle relative to said edge, and bonding material penetrating through said slits and joining successive convolutions of said sheet material to secure said roll in wound form.

4. An abrasive roll formed of spirally wound sheet material having an abrasive coating on one surface thereof, said sheet having a plurality of slits extending inwardly from one edge to form a fringe portion, and bonding material penetrating through said slits and adhering to successive convolutions of said sheet material to secure said roll in wound form.

5. An abrasive roll formed of convolutions of sheet material having an abrasive coating on one side and the other side uncoated, said roll having a bonded end, each convolution of said sheet slit inwardly from the edge thereof corresponding to said bonded end, bonding material disposed on said uncoated side in the area corresponding to said slits, said bonding material communicating through said slits and joining successive convolutions of said sheet material to secure said roll in convoluted form.

6. An abrasive roll as in claim 7 and wherein said slits extend laterally less than 1/8 the width of said roll.

7. The method of making an abrasive roll from an abrasive sheet having an abrasive coating on one surface thereof and the other surface uncoated comprising the steps of slitting one edge of said labrasive sheet in a manner to form a plurality of angular flaps having the point thereof disposed in a direction opposite to the direction of travel of said sheet when being wound, bending said flaps out of the plane of said sheet toward the uncoated side of said sheet, applying a bonding material to the uncoated side of said sheet in the area corresponding to said flaps and along the edges of said aps, winding said sheet into a roll, securing said roll in a Wound condition and curing said bonding material.

8. The method of making an abrasive roll from an abrasive sheet having an abrasive coating on one surface thereof comprising the steps of fringing one edge of said abrasive sheet, bending successive elements of said fringe No references cited. 

